Cord lock devices for releasably holding a cord or lace in a generally tensioned or gathered configuration, are known in the art. For example, cord lock devices are often used on fabric bags having a drawstring for closing the bag. The cord lock functions to hold, or lock, the drawstring in the closed position. Such cord lock devices are commonly used, for example, in gear bags and the like for camping and other outdoor activities. Cord lock devices are also frequently used for lacing systems for shoes, boots, and boot inserts. In a lacing system, the user can quickly tighten the lace by merely pulling upwardly on the lace or cord to achieve the desired tension, and sliding the cord lock device down over the cord to secure the cord, maintaining the tension in the cord.
In many prior art cord lock devices a rigid wedge-shaped element is disposed in a converging channel that is adapted to receive a cord therebetween. For example, in U.S. Pat. No. 198,086 to Dunn, a bag fastener is disclosed wherein a rigid wedge is disposed and biased in a case or envelope, such that a cord disposed between the wedge and case will be grasped therebetween by the biasing force of the spring. To release the cord, a user pulls up on the rigid wedge against the force of the spring to slide the wedge within the case thereby causing the sides of the wedge to move away from the sides of the case, and hence releasing the cord. The disclosed device, however, is relatively complex, requiring an embedded spring, and requires the use of rigid components, which may be relatively expensive.
Other devices that rely on the horizontal movement of a generally wedge-shaped device disposed between two sidewalls have also been proposed. For example, U.S. Pat. No. 5,894,639 to Boden et al. discloses a cord lock apparatus based on the same principal as Dunn, but wherein the spring element is formed integrally with the wedge or slide component. In U.S. Pat. No. 4,156,574, Boden discloses a somewhat similar apparatus wherein a pair of elongate arms at the top of the slide provides a biasing force through the movement of the cord to the slide. Similar devices are disclosed in U.S. Pat. No. 5,280,843 to Vartija et al, and U.S. Pat. No. 5,987,712 to Tucker. Although these prior art devices appear to perform their intended function, they all rely on moving a generally rigid, wedge-shaped element longitudinally within a converging channel or passageway, to engage or release a cord disposed therebetween.
Other cord lock devices are known wherein the user must grasp the cord lock from both sides and pinch together biased retaining members, in order to release the cord lock. A disadvantage of such cord locks is that they require that the user to grasp the device between the thumb and finger, and therefore a certain amount of dexterity is needed. The dexterity required may be particularly problematic—for example, in snow sporting applications where the user's hand may be cold and/or gloved, and the cord lock itself may be encrusted with snow.
Therefore a need remains for a relatively simple cord lock apparatus that requires minimal manual dexterity, and can be disengaged by the user with a single finger.